Zclassic Overwinter Upgrade with Equihash Parameters Tweaked and initial support for Sapling Upgrade Tests

3 min readJul 4, 2018

Financial freedom is the mantra of Zclassic. Fundamental to its attainment is fair distribution and decentralization of resources on top of privacy.

The ZclassicCE Team, together with the active Zclassic Community, intends to practice what we preach. We have reached out to every stakeholder and interested parties including the previous team who forked to Bitcoin Private ($BTCP) last March, our fellow developers and enthusiasts in the Zclassic Blue Team and the Anonymous Bitcoin Team ($ANON) who will be forking in September, as well as exchanges, mining pools and everyday miners to get their feedback regarding the virtual Bitmain monopoly on ASIC miner hardware production, centralization of hashpower, 51% attacks, double spending, and time warp vulnerability. We heard their collective voice loud and clear. A change in the parameters of the Equihash Algorithm used in ZCL is highly desired by a vast majority. We hope all our hard work gives justice to this overwhelming will.

Following on from BTCP team’s withdrawal from active Zclassic support and development, ZclassicCE was formed to step up and fill this void in early March. Our Discord server served as a vital nexus for many ZCL users and a lifeline for most. After the public release of ASIC’s in the wild, it kindled lively discussions all over the internet. FPGA’s were cited as a possible “solution”. Others suggested that if ASIC’s were generally adopted, it would stabilize ZCL hashrates with superior hashpower, however both Bitmain and Innosilicon Equihash miners are not generally available nor affordable yet, and it weakened this rather tempting argument. We have initiated a collaborative strategy with the Blue Team and Anon Team to address this and other common issues we mutually encounter in Zclassic. This is highlighted in a recent interview with our own @Vic and Jake of ANON. The community is thrilled with the prospects of three teams coming together for the common good of Zclassic.

Inspired by the successful activation of Equihash upgrades in BitcoinZ and Bitcoin Gold, and the Overwinter Upgrade of Zcash, we are taking a bold step forward for Zclassic’s future.

Having studied the entire ecosystem and in keeping up to date with the latest code development of upstream Zcash, we have decided that we are following the direction Zcash is taking in the long run. Minus the founders’ tax, of course. Zclassic is a classic fork of Zcash, and always will be. We will follow through with Overwinter and Sapling Upgrades within a few months of their respective activation in Zcash. But with a twist. @bitcartel has maintained a branch of Zcash with Equihash tweaks on top of Overwinter activation. (It is interesting and important to note that the Equihash<144,5> parameters was seriously considered as the default parameters in the original release of Zcash, as “ASIC-resistance” was one of its goals at launch.) This is “out of schedule” for Zcash and they intend to stick to Sapling timeline commitment. The Zcash Foundation has also stated they will be studying the situation for at least a few more months. Therefore, any official Zcash response will definitely be after Sapling activation. In the meantime, ZclassicCE will adopt the quasi-canonical variant of Zcash with new Equihash parameters as implemented by @nimbosa for Zclassic. We will continually refine this implementation with the help of the community while receiving reviews and feedback from everyone concerned. Any development or algorithm changes in Zcash after Sapling will be monitored and evaluated by Zclassic developers later this year.

Technical articles, guidelines, checklists and timetables will be published at the soonest possible time to help everyone prepare for Zclassic Overwinter Upgrade. So please stay tuned for further announcements. Our target block height for Overwinter activation is 375,748 or around 29th August 2018, to give ample preparation testing wallet updates, service upgrades and activation dry-runs. The initial implementation can be found here: https://github.com/ZclassicDev/zclassic/tree/v1.1.1-ALPHA (with draft release notes here). Join us on GitHub or on Discord.

Please contact us below if you would love to help and contribute:

Website : https://zclassic-ce.org/
Discord : https://discord.gg/NRdczWC
Telegram : https://t.me/ZClassicCoin (Official)
Telegram : https://t.me/ZclassicCE (Community)
Twitter : https://twitter.com/ZclassicDev (Community)
GitHub : https://github.com/ZclassicDev (Community)
GitLab : https://gitlab.com/zclassic
Facebook : https://FB.com/ZclassicCE
Reddit : https://www.reddit.com/r/ZClassic

Our core team’s donation multisig wallets are here for your perusal and will be exclusively used for development and maintenance of Zclassic infrastructure and testing of network upgrades:

ZCL (Zclassic, ZEC or HUSH t-addr):

BTCP (Bitcoin Private t-addr):

BTC (Bitcoin SegWit native Bech32):

BTC (Bitcoin SegWit P2WPKH-in-P2SH):

BTC (Bitcoin non-SegWit):

We thank you for your strong support of Zclassic!